Free-wheeling clutch



[45] Patented 'prospeltt, 73, kv. 19, Penn, U.S.S.R. 211 AppLNo. 762,941221 Filed Sept. 26, 1968 Dec.22, 1970 [54] FREE-WHEELING CLUTCH 4Claims, 3 Drawing Figs.

Q United States Patent l 13,548,982

[72] Inventors Pavel Alexandrovich Soloviev [50] Field of Search l92/38,44,

Korusolnolsky prospekt, 90, kv. 21; 45, 27; 188/82.84; 81/59.l GeorgPetrovich Kalashnikov, ul. Geroev Khasana, 16, kv. 53; Lev IzrailevichReferences Cited Kantor, ul. Geroev Khasana, 30, kv.-37; UNITED STATESPATENTS m N'Wwkh w Kommmolsky 2,068,773 1/1937 Slider ,1 192/45 PrimaryExaminer-Allan D. Herrmann Attorney-Waters, Roditi, Schwartz & NissenABSTRACT: A freewheeling clutch of a roller type includes a drivingsprocket, a driven race, a roller cage interposed between the sprocketand the race, the roller cage supporting spaced rollers positioned inrecesses between radially extending spaced projections providedcircumferentially on the sprocket, and a plurality of stops resilientlybiasing against the opposite axial ends of the rollers, which stops aresupported by the race to rotate therewith.

FREE-WHEELING CLUTCH The present invention relates to devices forunidirectional transmission of torque and, more particularly, toroller-type freewheeling clutches (overrunning clutches).

Clutches according to this invention are employed in power plants oftransport vehicles, for example, in a helicopter power plant. 7

In known roller-type freewheeling clutches, rotation from the drivingshaft to the driven shaft is transmitted by rollers wedged betweendriving and driven elements, ie a sprocket and race. To provide for asimultaneous wedging of all the rollers at one time, the latter areplaced in cylindrical seats of a roller cage acted upon'by coil springs.The springs are set between projections of the sprocket and the rollercage and constantly press the rollers through the roller cage againstthe working surfaces of the sprocket and the race (cf. U.S. Pat. No.2,068,773,class 192-45, 1937).'

A disadvantage of the known freewheeling clutch is the constant pressureof the rollers against the working surfaces of the sprocket and therace. With a reverse direction of the torque (at the overrunning duty)this causes rotation of the rollers, which results in a rapid wear ofthe working surfaces of the rollers, sprocket and race.

In addition, the design of the roller cage is complicated due tofastening of the springs thereto, as well as due to the provision ofseats with cylindrical surfaces.

An object of the present invention is to eliminate the foregoingdisadvantages and to provide a freewheeling clutch, which has a longservice life and is relatively simple in design.

in accordance with the invention and in the accomplishment of the aboveand other objects thereof, the rollers are resiliently clamped at theirends, projecting from the seats of the roller cage, between stopsrotating together with the driven element of the clutch. The frictionforce developed between the surfaces of the stops and theroller endsprevents the rollers from being displaced along the circumference at thebeginning of rotation of the driving element of the clutch (thesprocket) when the engine starts. At this moment, all the rollers arewedged instantly and simultaneously.

A side pressing of the rollers prevents them from skewing in the rollercage seats having rectilinear surfaces.

It is feasible to fashion the stops as rings, at least one of said ringsbeing displaceable relative to the driven part of the clutch along therotation axis in order to provide a resilient clamping of the rollers.

The resilient clamping of the rollers with the aid of such rings may bebetter accomplished if either a wave-shaped or a flat ring is used.

The invention is further exemplified by the description of an embodimentthereof and accompanying drawings, in which:

FIG. 1 shows a longitudinal section of a freewheeling clutch inaccordance with the invention; 1

FIG. 2 is an axonometric view of a part of said clutch; and

FIG. 3 shows an embodiment of an elastic element for clamping therollers, fashioned as a flat spring.

The freewheeling clutch of the present invention consists of a drivingelement, a sprocket 1 (FIGS. 1 and 2), transmitting the torque to adriven element, a race 2, through rollers 3 spaced at equal distancesfrom each other by a roller cage 4.

The race 2 has a cylindrical inner surface 5, concentrically arrangedrelative to the periphery of the sprocket l, and is rigidly coupled to adriven shaft 6.

The sprocket l is secured to a driving shaft 7 by means of a splinedconnection. The sprocket periphery is provided with a plurality ofcircumferentially spaced. radially extending projections 8. Theclearance between the inner cylindrical surface 5 of the race 2 and theperiphery of the sprocket 1 has alternating narrowing and wideningportions, the rollers 3 being wedged in the former when the clutchtransmits the torque from the driving shaft 7 to the driven shaft 6.With a reverse direction of the torque (at the overrunning duty) therollers slide over the projections 8 into the recesses 9. The process isspeeded up by means of axially extending projections 10 of the sprocketl which, when thrust against the edge 11 of a cut 12 of a flange 13 ofthe roller cage 4, stop the latter.

Stop rings 14 and 15 are p aced at die ends of the rollers 3,

which rings revolve together with the race 2 and are connected with itby means of pins 16 entering the ring slots and secured in the race.

The rings 14 and 15 are capable of axial displacement.

The rollers 3 are resiliently clamped between the rings 14 and 15 by awave-shaped spring 17 placed between the ring 14 and a ring 18 embracinga ball bearing 19.

Friction between the ends of the rings 14 and i5 and the ends of therollers 3 prevents the latter from being displaced when the sprocket 1rotates.

Therefore, at the very beginning of rotation of the sprocket l therollers 3 clamped at the ends are smoothly and almost instantly clampedin the narrowing portions of the clearance between the race 2 and thesprocket l'.

The resilient element of the clutch may be fashioned as a flat ringspring 20 (FIG. 3) with projections 21 alternating at the lateral sidesof the spring ring.

It is possible to make one of the stops integral with the driven elementof the clutch. This reduces the number of the clutch parts, although thedriving element becomes somewhat more complicated.

A test model of the freewheeling clutch according to the presentinvention is capable of transmitting 5,500 hp. at 7,800 r.p.m. I

Switching of the clutch occurs after the driving shaft rotates by 5 to15 of its turn from the out-of-gear position.

We claim:

l. A freewheeling clutch of roller type, comprising: a drivingsprocket;a driven race; said sprocket being provided with a plurality ofcircumferentially spaced projections; a plurality of spaced rollerspositioned between said projections of said sprocket; a roller cagesupporting said rollers; and means supporting a plurality of stops onsaid race to rotate therewith, said stops being arranged axiallyopposite the ends of said rollers, said rollers being resiliently andaxially pressed at said ends between said stops. 1

2. A freewheeling clutch as set forth in claim 1, in which at least oneof said stops is a ring and connected to said race as to be axiallymovable relative to the rotation axis of said clutch.

3. A freewheeling clutch as set forth in claim 2, in which said rollersare resiliently clamped between said ring stops by means of at least onewave-shaped ring spring.

, 4. A freewheeling clutch as set forth in claim 2, in which saidrollers are resiliently clamped between said ring stops by means of atleast one flat ring spring.

